This document discusses the differences between pull-based and push-based monitoring approaches. It notes that both approaches require instrumenting applications, and that sometimes one is easier than the other depending on the situation. Specifically, pull may be easier for monitoring millions of IoT devices globally, while push may be difficult for monitoring metrics from MySQL. The document also thanks Prometheus, the CNCF, and the OpenMetrics initiative for standardizing the pull method and metrics format. It highlights how Kapacitor now integrates Prometheus' service discovery and scraping code to enable pull-based monitoring using InfluxDB.